Effects of Abandoned Mine Drainage on Crayfish Distribution Along a PH Gradient

Abstract

The Kiski-Conemaugh river basin in western Pennsylvania is heavily impacted by drainage from abandoned coal mines. Invertebrate diversity is decreased, with only acid tolerant species inhabiting the most affected streams. Crayfish, which are not acid tolerant, disappear as streams approach pH = 6.0. Little, however, is known about the distribution of crayfish in streams of intermediate pH. We sampled water quality and crayfish and invertebrate abundance at five sites along the pH gradient of Little Paint Creek, near Johnstown, PA. The first site (pH > 8.0) is an unimpacted area upstream from a coal refuse pile. The second site (7.0 < pH < 8.0), at the upstream edge of the pile, has been impacted at some time, but is not impacted now. The remaining sites (pH < 7.0), downstream from the mine, are heavily impacted year round. Crayfish abundance as determined by kick net and hand collecting, declines downstream, from site 1 to site 2. Crayfish were not found at the downstream sites.